Site-oriented absorption function and its regulation mechanism

位点吸收功能及其调控机制

• 批准号: 06660163
• 负责人: IWAMI Kimikazu
• 金额: $ 1.28万
• 依托单位: Kyoto Prefectural University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1994
• 资助国家: 日本
• 起止时间: 1994 至 1995
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-06660163/
• 关键词: jejunoileal transposition; adaptation gut functions; hyperplasia of villi; transport system for bile acide; Na^+; bile acid cotransporter; site-oriented gene expression; 遺伝子発現; 空回腸位置置換手術; 術後過形成; 空回腸部分切除手術; 小腸機能適応

Male Wistar rats which had undergone resection (R) or transposition (T) on the jejunoileum were examined for functional and morphological changes in their residual intestinal tract. Villous length and mucosal weight of doudenum, jejunum, and ileum were much more in group T than in group R.Pancreatic hypertrophy was also observed for group T.There was no significant difference between both the groups in protein/RNA ratio of mucosa as well as specific activity of brush border membrane-bound enzymes. As for a Na^+-dependent transport for bile acid (taurocholate), its transmural transport was measured using several everted sacs from the whole small intestine. As a result, sctive transport was found to occur in the very everted sac from the intrinsic distal ileum irrespective of resection or transposition. The expression experiment with Xenopus laevis oocytes revealed that the Na^+-dependent taurocholate uptake increased with increasing amounts of mucosal poly (A)^+RNA,exclusively appearing in the oocytes inclusive of ileal mRNA.Such a site-specific expression was ascertained by Northern blot analysis using a specific probe. It has become by Northern blot analysis using other probes that c-myc and IGF-1 mRNA don't emerge 2 days after operation and that neither c-fos nor ODC mRNA differs in emergence between R and T groups. Mucosal stimulation such as intraluminal food transit and enteral nutrition should be considered for a plausible explanation of unknown factors affecting ileal hyperplasia.

对空回肠切除（R）或移位（T）的雄性Wistar大鼠进行了检查，以了解其残留肠道的功能和形态变化。T组大鼠十二指肠、空肠和回肠的绒毛长度和粘膜重量均显著高于R组，胰腺肥大。两组大鼠粘膜蛋白/RNA比值和刷状缘膜结合酶的比活性无显著差异。至于胆汁酸（牛磺胆酸盐）的Na^+依赖性转运，使用整个小肠的几个翻转囊来测量其跨壁转运。结果，无论是切除还是移位，在从回肠远端固有段外翻的肠囊内均发现了主动转运。非洲爪蟾卵母细胞的表达实验显示，Na^+依赖性牛磺胆酸盐摄取随粘膜poly（A）^+RNA量的增加而增加，这种情况只出现在包括回肠mRNA在内的卵母细胞中，通过使用特异性探针的北方印迹分析，证实了这种位点特异性表达。用其他探针进行北方印迹分析发现，术后2天，c-myc和IGF-1 mRNA均未出现，而c-fos和ODC mRNA在R组和T组之间的出现也无差异。对于影响回肠增生的未知因素，应考虑粘膜刺激，如腔内食物转运和肠内营养。